JP3027351B2 - Pressure control valve and pressure control method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure control valve and a pressure control method thereof.

[0002]

2. Description of the Related Art Conventionally, as a pressure control valve, for example, there is a pressure control valve as disclosed in Japanese Patent Application Laid-Open No. 2-284213. In this pressure control valve, an on-off valve that opens and closes a gas flow path is opened and closed by reciprocating motion of a pressure receiving member, and the pressure receiving member is reciprocated according to pressure fluctuations of the pilot chamber.
Further, in this pressure control valve, a pressure sensor for detecting the pressure on the output port side of the flow path, an air supply side solenoid valve for controlling the pressure supplied from the supply port side of the flow path to the pilot chamber, An exhaust-side solenoid valve for controlling the pressure discharged from the pilot chamber to the outside is provided. The controller opens and closes each solenoid valve based on the difference between the pressure detected by the pressure sensor and the set pressure, and supplies or discharges pressure to the pilot chamber, thereby controlling the pressure in the pilot chamber. The on-off valve is opened and closed according to the fluctuation of the pressure, and the pressure of the output port is controlled to the set pressure.

[0003]

However, in the conventional pressure control valve, the load capacity of a pressure-supplied body such as a cylinder to which a pressurized gas is supplied from an output port is large, and the pressure of the output port is set to a set pressure. If it takes a long time to reach, that is, if the state where the output port pressure is lower than the set pressure becomes longer, the controller controls the air supply side solenoid valve to open so that the output port pressure approaches the set pressure sooner. To increase the pressure in the pilot chamber. In other words, in this pressure control valve, the solenoid valve is controlled to open and close based on the difference between the set pressure and the output port pressure.If the output port pressure is lower than the set pressure for a longer time, the pilot chamber pressure will increase. Very high. As a result, the on-off valve is greatly opened, and a large amount of gas at the supply port is supplied to the output port, so that the pressure at the output port can be brought close to the set pressure at high speed, but the pressure in the pilot chamber is reduced at the output port. Since the pressure is high regardless of the difference between the pressure and the set pressure, the return of the on-off valve when the pressure of the output port reaches the set pressure is delayed, and accurate pressure control cannot be performed.

In order to solve this problem, for example, a configuration is conceivable in which the opening of the air supply side solenoid valve is controlled so that the pressure at the output port gradually approaches the set pressure.
In this case, high-speed pressure control cannot be expected.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to perform high-speed and high-precision pressure control even when the load capacity of a pressure-supplied body such as a cylinder is large. And a pressure control method therefor.

[0006]

[0007]

Means for Solving the Problems To achieve the above object,
Therefore, the first invention provides a valve body that opens and closes a flow path forming an input port and an output port, and divides a feedback chamber into which the pressure of the flow path on the output port side is introduced, and a pilot chamber by a pressure receiving body. The pressure control valve for forming and controlling the pressure of the pilot chamber to change the pressure of the pilot chamber to open and close the valve body via a pressure receiving body in accordance with the pressure fluctuation and control the opening and closing of the flow path. A passage for introducing the pressure of the flow path into the feedback chamber has an effective flow path cross-sectional area smaller than the effective flow path cross-sectional area of the flow path on the output port side, and the feedback chamber is moved when the pressure receiving member moves. A pressure sensor for detecting the pressure fluctuation, and a control means for changing and controlling the pressure of the pilot chamber based on a detection signal of the pressure sensor. It is intended.

According to a second aspect of the present invention, there is provided a valve element for opening and closing a flow path in which an input port and an output port are formed, and a feedback chamber in which the pressure of the flow path on the output port side is introduced and a pilot chamber are formed by a pressure receiving element. By forming a section and controlling the pressure of the pilot chamber to change, the pressure control method of a pressure control valve that opens and closes the valve body via a pressure receiving body according to the pressure fluctuation, and controls the opening and closing of the flow path. The passage for introducing the pressure of the flow path on the output port side into the feedback chamber has an effective flow path cross-sectional area smaller than the effective flow path cross-sectional area of the output port-side flow path, and the pressure receiving member has moved. In such a case, the pressure in the feedback chamber is made to fluctuate instantaneously, and the pressure fluctuation is detected by a pressure sensor. It is obtained so as to change control force.

[0009]

Therefore, according to the first or second aspect of the invention, when the pressure in the pilot chamber rises and the pressure receiving member is moved, the pressure entering the feedback chamber is instantaneously compressed and becomes higher than the pressure of the output port. The increased pressure in the feedback chamber is detected by the pressure sensor. That is, since the detected pressure is higher than the pressure of the output port at the time of the detection, the pressure detected by the pressure sensor is detected as a pressure that rises faster than the actual port pressure. When the control means is controlled based on the pressure, even when it takes time for the output port pressure to reach the set pressure, the time can be apparently shortened, and the pressure in the pilot chamber abnormally increases. Nothing.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a pressure control valve will be described below with reference to the drawings. As shown in FIG. 1, a gas passage 2 is formed in the valve housing 1, and both ends of the gas passage 2 are an air supply port 3 and an output port 4, respectively. An opening / closing unit 5 for opening and closing the flow path 2 includes a valve seat 6 and a valve body 7.
The valve element 7 is slidably fitted into a back chamber 8 formed at a position facing the valve seat 6. The valve element 7 is urged toward the valve seat 6 by a spring 9. In the state of FIG. 1, the valve element 7 is pressed against the valve seat 6, and the flow path 2 is closed. The valve body 7 is formed with a communication hole 7a for communicating the output port 4 side of the flow path 2 with the back chamber 8, and through the communication hole 7a, the output port 4 side of the valve body 7 and the back chamber 8 side. The pressure of the valve body 7 is pressure-balanced by equalizing the pressures.

Another flow path 10 is the output port 4 of the flow path 2
The valve housing 1 is formed so as to communicate with the side, and an end of the valve housing 1 serves as an exhaust port 11. Further, the first housing cover 12 is attached to the upper surface of the valve housing 1. Opening / closing section 1 for opening and closing the flow path 10
3 has a valve seat 14 and a valve body 15, and the valve body 15
Are slidably fitted into a back chamber 16 formed in the first housing cover 12 at the position opposite to the first housing cover 12. And
The valve element 15 is urged toward the valve seat 14 by a spring 17. In the state of FIG. 1, the valve element 15 is pressed against the valve seat 14, and the flow path 10 is closed. The valve body 15 is formed with a communication hole 15a for communicating the output port 4 side of the flow path 2 with the back chamber 16, and the valve body 1 is connected through the communication hole 15a.
The valve body 15 is pressure-balanced by equalizing the pressure on the output port 4 side and the back chamber 16 side.

A second housing cover 18 is mounted on the upper surface of the first housing cover 12 and covers both covers 1.
A pressure chamber 19 is formed between the two covers 2, 18, and a pressure receiving body 20 is disposed between the two covers 12, 18 so as to be located in the pressure chamber 19. The pressure receiving body 20 is the second
Housing cover 18 and first housing cover 12
And a pressure receiving plate 22 that sandwiches the diaphragm 21 from both sides. Pressure receiver 20 and second housing cover 18
The pressure receiving body 20 divides the pressure chamber 19 so that the pilot chamber 23 is formed between the pressure receiving body 20 and the feedback chamber 24 is formed between the pressure receiving body 20 and the first housing cover 12.

The rod 25 is fixed to the pressure receiving body 20 by a nut 26. The rod 25 and the pressure receiving body 20 are
5 can reciprocate integrally along the axial direction.
The rod 25 extends through the first housing cover 12 and the valve body 15 to near the upper surface of the valve body 7. A ring 27 is fixed to a substantially intermediate portion of the rod 25, and the ring 27 can be engaged with the lower surface of the valve body 15. Then, the internal pressure of the pilot chamber 23 becomes larger than the internal pressure of the feedback chamber 24,
When the rod 25 is moved down together with 0,
Abuts against the valve body 7 to push down the valve body 7 against the urging force of the spring 9 to open the opening / closing section 5. Further, when the internal pressure of the feedback chamber 24 becomes larger than the internal pressure of the pilot chamber 23 and the rod 25 is moved upward together with the pressure receiving body 20, the ring 27 of the rod 25 engages with the valve body 15 and 15 is pushed up against the urging force of the spring 17 to open the opening / closing section 13.

The air supply passage 28 is connected to the air supply port 3 of the flow path 2.
The valve housing 1, the first housing cover 12, and the second housing cover 18 are formed so as to connect the side and the pilot chamber 23. An air supply side valve 29 composed of an electromagnetic valve is provided with a second valve so as to open and close the air supply passage 28.
The high pressure gas on the air supply port 3 side is introduced into the pilot chamber 23 as needed to increase the internal pressure. The exhaust passage 30 is formed in the second housing cover 18 so as to communicate the pilot chamber 23 with the outside. Exhaust valve 3 consisting of a solenoid valve
1 is provided on the second housing cover 18 so as to control the opening and closing of the exhaust passage 30, and discharges gas in the pilot chamber 23 to the outside as necessary to reduce the internal pressure. The control means is constituted by the air supply side valve 29 and the exhaust side valve 31.

The feedback passage 32 connects the valve housing 1 and the first housing cover 1 so as to connect the output port 4 side of the flow passage 2 to the feedback chamber 24.
2 is formed. Therefore, the pressure on the output port 4 side of the flow path 2 is introduced into the feedback chamber 24. The pressure sensor 33 is provided on the second housing cover 18,
The passage 34 is connected to the feedback passage 32 and the pressure sensor 3.
3 so that the second housing cover 1 communicates with the lower surface of the second housing cover 1.
8 is formed. The pressure sensor 33 detects the internal pressure of the passage 34 connected to the output port 4 of the flow path 2 and the feedback chamber 24 via the feedback passage 32 and outputs a detection signal.

The cover 35 is a second housing cover 18.
Is mounted on the first housing cover 12 so as to cover the air supply side valve 29, the exhaust side valve 31, and the pressure sensor 33.
Is covered. An exhaust hole 36 is formed on a side surface of the cover 35. A board 37 is provided in the cover 35, and a control circuit for controlling the opening and closing of the supply valve 29 and the exhaust valve 31 based on the detection signal from the pressure sensor 33 is mounted on the board 37. I have. That is, the pressure sensor 33
If the pressure on the output port 4 side detected by the above is lower than the input set pressure, the air supply side valve 29 is opened to supply the pressure on the air supply port 3 side of the flow path 2 into the pilot chamber 23. I do. If the pressure on the output port 4 side is higher than the set pressure, the exhaust side valve 31 is opened to discharge the pressure in the pilot chamber 23 to the outside.

A passage 39 is provided between the passage 34 and the pilot chamber 2.
3 and an orifice 38 is arranged in a passage 39 thereof. This orifice 38
Is for releasing the pressurized gas in the pilot chamber 23 to the output port 4 side when the internal pressure in the pilot chamber 23 is higher than the pressure in the output port 4 side. That is, when the load capacity of a pressure-supplied body such as a cylinder to which the pressure gas is supplied from the output port 4 is large, and the pressure on the output port 4 side is lower than the set pressure and it takes time to reach the set pressure, The pressurized gas in the pilot chamber 23 is sent to the output port 4 via the orifice 38.

Next, the operation of the pressure control valve configured as described above will be described. FIG. 1 shows a state in which the pressure in the pilot chamber 23 and the pressure in the feedback chamber 24 are in equilibrium. In this state, the rod 25 is in the neutral position, and the supply / exhaust-side opening / closing parts 5, 13 are closed. ing.

When the pressure gas is supplied to the air supply port 3 and the pressure on the output port 4 side detected by the pressure sensor 33 is lower than the set pressure, the air supply side valve 29 is controlled by the control circuit on the substrate 37. Is controlled to open and the pilot room 2
The pressure on the air supply port 3 side of the flow path 2 is supplied into the inside 3. As a result, the feedback chamber 24 communicating with the output port 4
Is lower than the internal pressure of the pilot chamber 23, and the pressure receiving body 20 is moved down according to the pressure difference. Accordingly, the rod 25 is moved downward, and the lower end of the rod 25 comes into contact with the valve body 7 to push down the valve body 7 to open the opening / closing section 5. As a result, the pressurized gas in the air supply port 3 is supplied to the output port 4, and the pressure on the output port 4 side is increased to the set pressure.

If the pressure on the output port 4 side detected by the pressure sensor 33 is higher than the set pressure, the substrate 37
The exhaust side valve 31 is controlled to open by the above control circuit, and the pressurized gas in the pilot chamber 23 is discharged to the outside. Thereby, the internal pressure of the feedback chamber 24 becomes larger than the internal pressure of the pilot chamber 23, and the pressure receiving body 20 is moved upward according to the pressure difference. Accordingly, the rod 25 is moved upward, and the ring 27 of the rod 25 is engaged with the valve body 15 to push up the valve body 15 to open the opening / closing section 13.
As a result, excessive pressure gas in the output port 4 is
Through the exhaust port 11 to the atmosphere, and the pressure on the output port 4 side is reduced to the set pressure.

Here, if the load capacity of the pressure-supplied body such as a cylinder is large, it takes time for the pressure on the output port 4 side to reach the set pressure. That is, the state in which the pressure on the output port 4 side is lower than the set pressure becomes longer, and the control circuit on the substrate 37 controls the opening of the air supply side valve 29 to increase the internal pressure of the pilot chamber 23. Then, the pressure in the pilot chamber 23 becomes significantly higher than the pressure on the output port 4 side, and the pressure gas in the pilot chamber 23
The pressure is released to the output port 4 side via the air supply port 3, and the pressure on the output port 4 side is rapidly increased in combination with the pressure of the gas supplied from the air supply port 3.
Internal pressure does not rise abnormally. Therefore, the pressure on the output port 4 side can approach the set pressure at a high speed, and when the pressure on the output port 4 side reaches the set pressure, the valve element 7 can immediately return to the closed state, and the output port 4 side Does not exceed the set pressure. Therefore,
Even if the load capacity of the pressure-supplied body is large, high-speed and accurate pressure control can be performed, and high accuracy can be maintained.

If the load capacity of the pressure-supplied body is not so large, the amount of pressure released from the orifice 38 decreases, and the pressure is increased based on the opening / closing operation of the opening / closing portions 5 and 13 as described above. Control is performed. Therefore, stable pressure control can be performed regardless of the load capacity of the pressure-supplied body.

Next, another example of this embodiment will be described with reference to FIG. Now, in this pressure control valve of another example, the feedback passage 32 and the passage 34 are communicated via the feedback chamber 24. When a pressure gas is supplied to the air supply port 3 and the pressure on the output port 4 side detected by the pressure sensor 33 is lower than the set pressure, the air supply side valve 29 is controlled to open as described above. , The internal pressure of the pilot chamber 23 is increased, and the pressure receiving body 20 is moved downward. At this time, the feedback path 32
The pressure entering the feedback chamber 24 via the pressure chamber is instantaneously compressed to a pressure higher than the output pressure of the output port 4, so that the downward movement of the pressure receiving body 20 is moderated and the internal pressure of the feedback chamber 24 is increased. Is detected by the pressure sensor 33 via the passage 34. Since the detected pressure is higher than the output pressure of the output port 4 at the time of the detection, the pressure detected by the pressure sensor 33 is set as a pressure that rises earlier than the actual output pressure of the output port 4. Is detected. That is, the pressure detection signal sent from the pressure sensor 33 to each of the valves 29 and 31 is sent earlier, the load capacity of the pressure-supplied body such as the cylinder is large, and the pressure on the output port 4 side is higher than the set pressure. Even when the low state becomes long, the low state can be apparently shortened, and in combination with the effect of the passage 39 and the orifice 38 of the above-described embodiment, the abnormal increase in the internal pressure of the pilot chamber 23 is prevented. Thus, stable pressure control can be performed regardless of the load capacity of the pressure-supplied body. The above-described effect is effective even when the passage 39 and the orifice 38 are not provided.

The above embodiment is not limited to this . For example, an orifice 38 is disposed in the exhaust passage 30, or a variable orifice, for example, a rubber orifice is used as the orifice 38, and the pilot chamber 23 and the output port 4 are used. For example, the gas passage amount may be changed in accordance with the pressure difference with the exhaust side, or the flow path and the opening / closing section may be provided at only one place except for the flow path 10 and the opening / closing section 13 on the exhaust side. The configuration of each unit can be arbitrarily changed and embodied without departing from the spirit of the present invention.

[0026]

[0027]

As described in detail above, claims 1 and 2
According to the invention described in Item 2 , even when it takes time for the pressure of the output port to reach the set pressure, the time can be apparently shortened, and the pressure in the pilot chamber is prevented from abnormally increasing. Therefore, pressure control can be performed at high speed and with high accuracy regardless of the load capacity of a pressure-supplied body such as a cylinder.

[Brief description of the drawings]

Figure 1 is a cross-sectional view showing an embodiment of a pressure control valve.

FIG. 2 is a sectional view showing another example of the pressure control valve.

[Explanation of symbols]

2 flow path, 3 air supply port (input port), 4 output port, 5 opening / closing section, 7 valve body, 20 pressure receiving body, 23 pilot chamber, 29 air supply side valve (control means), 31 exhaust side valve (control means) ), 32 feet back aisle (passage), 3
3 pressure sensor, 34 passage, 38 orifice, 39
Passage, 40 pressure sensor.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G05D 16/00-16/20

Claims (2)

(57) [Claims] An input port (3) and an output port (4).
A valve body (7) for opening and closing a flow path (2) in which a pressure chamber is formed, and a feedback chamber (24) into which pressure of the flow path (2) on the output port (4) side is introduced, and a pilot chamber (23). Is formed by the pressure receiving body (20), and the pilot chamber (2) is formed.
In the pressure control valve for controlling the change of the pressure of 3), the valve (7) is opened and closed via the pressure receiving body (20) in accordance with the pressure fluctuation, and the flow path (2) is controlled to be opened and closed. A passage (32) for introducing the pressure of the flow path (2) on the output port (4) side into the feedback chamber (24);
The effective flow path cross-sectional area is smaller than the effective flow path cross-sectional area of the flow path (2) on the output port (4) side, and the pressure of the feedback chamber (24) when the pressure receiving body (20) moves. A pressure sensor (33) for detecting the pressure fluctuation is provided, and the pressure of the pilot chamber (23) is changed and controlled based on a detection signal of the pressure sensor (33). A pressure control valve comprising means (29, 31). 2. An input port (3) and an output port (4).
A valve body (7) for opening and closing a flow path (2) in which a pressure chamber is formed, and a feedback chamber (24) into which the pressure of the flow path (2) on the output port (4) side is introduced, and a pilot chamber (23). Is formed by the pressure receiving body (20), and the pilot chamber (2) is formed.
3) The pressure of the pressure control valve for controlling the opening and closing of the valve body (7) via the pressure receiving body (20) in accordance with the pressure fluctuation by controlling the change of the pressure of 3). In the pressure control method, a passage (32) for introducing the pressure of the flow path (2) on the output port (4) side into the feedback chamber (24) has an effective cross-sectional area of the output port (4). Smaller than the effective flow path cross-sectional area of the flow path (2) on the side of
0) is moved so that the pressure in the feedback chamber (24) fluctuates instantaneously when it moves. The pressure fluctuation is detected by the pressure sensor (33), and based on the detection signal of the pressure sensor (33). Te, the pressure control method of the pressure control valve being characterized in that so as to change control pressure of the <br/> pilot chamber by the control means (29, 31) (23).